2008 IceCube Update - Section 9

IX. FUTURE PLANS

IceCube completion is scheduled for 2011. In addition to the 80 baseline
strings, we are also developing a Deep Core infill array. Deep Core will
consist of 6 additional strings with a smaller, 72 m grid spacing. The DOMs
will use new phototubes with 25% higher quantum efficiency. They will be
spaced every 7 m in the deepest, clearest 350 m of ice. In addition, the rest
of IceCube will serve as a veto region surrounding Deep Core, allowing for
the rejection of cosmic-ray muons and other non-contained backgrounds. The
higher granularity, improved optical sensitivity and surrounding veto will
give Deep Core a much lower threshold than IceCube, as low as 10 GeV.

IceCube collaborators are also studying prototype radio and acoustic neutrino
detectors. These are sensitive to coherent radio-Cherenkov emission from
neutrino-induced electromagnetic and hadronic showers and the shock-wave
produced by local heating from neutrino induced showers respectively. The
radio and acoustic signals should have much larger absorption lengths than
light, so these techniques might be usable to build a much larger (100
km3)array than IceCube. However, because of the technique used,
the array would have a much higher energy threshold, perhaps (1017
eV).